For the design of a PV system, which aspect must be documented and stamped by a licensed professional?

In the design of a photovoltaic (PV) system, documenting the maximum DC voltage calculations is crucial because these calculations ensure that the system operates within safe limits and complies with electrical codes and standards. It is essential for a licensed professional to review and stamp these calculations because they verify the safety and efficacy of the system under various conditions, such as temperature changes, shading effects, and variations in load. This validation helps prevent electrical hazards and ensures that the systems are correctly designed to handle the expected voltage levels, thus adhering to National Electrical Code (NEC) requirements.

Other aspects, while important for the overall installation and efficiency of the PV system, do not require the same level of professional oversight. For example, conduit specifications, installation diagrams, and equipment mounting instructions involve construction and installation practices that, while they must meet code, do not automatically necessitate a formal stamp from a licensed professional in the same way that voltage calculations do. The emphasis on maximum DC voltage calculations underscores the importance of safety, regulatory compliance, and effective system design in PV installations.